/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | foam-extend: Open Source CFD
   \\    /   O peration     | Version:     4.1
    \\  /    A nd           | Web:         http://www.foam-extend.org
     \\/     M anipulation  | For copyright notice see file Copyright
-------------------------------------------------------------------------------
License
	This file is part of foam-extend.

	foam-extend is free software: you can redistribute it and/or modify it
	under the terms of the GNU General Public License as published by the
	Free Software Foundation, either version 3 of the License, or (at your
	option) any later version.

	foam-extend is distributed in the hope that it will be useful, but
	WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
	General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with foam-extend.  If not, see <http://www.gnu.org/licenses/>.

Class
	Foam::octreeDataTriSurface

Description
	Encapsulates data for octree searches on triSurface.

SourceFiles
	octreeDataTriSurface.C

\*---------------------------------------------------------------------------*/

#ifndef octreeDataTriSurface_H
#define octreeDataTriSurface_H

#include "treeBoundBoxList.H"
#include "labelList.H"
#include "point.H"
#include "triSurface.H"
#include "linePointRef.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{

// Forward declaration of classes
template<class Type> class octree;


class octreeDataTriSurface
{
	// Static data

		//- tolerance on linear dimensions
		static scalar tol;

	// Private data

		const triSurface& surface_;

		const treeBoundBoxList allBb_;

		// Extra data to speed up distance searches.
		// Triangles expressed as base + spanning vectors
		pointField base_;
		pointField E0_;
		pointField E1_;
		scalarList a_;
		scalarList b_;
		scalarList c_;


	// Private Static Functions

		//- fast triangle nearest point calculation. Returns point in E0, E1
		//  coordinate system:  base + s*E0 + t*E1
		static void nearestCoords
		(
			const point& base,
			const point& E0,
			const point& E1,
			const scalar a,
			const scalar b,
			const scalar c,
			const point& P,
			scalar& s,
			scalar& t
		);

		//- Calculate bounding boxes for triangles
		static treeBoundBoxList calcBb(const triSurface&);


	// Private Member Functions

		//- nearest point in xyz coord system
		point nearestPoint(const label index, const point& P) const;


public:

	// Declare name of the class and its debug switch
	ClassName("octreeDataTriSurface");


	// Constructors

		//- Construct from triSurface. Holds reference. Bounding box
		//  calculated from triangle points.
		octreeDataTriSurface(const triSurface&);

		//- Construct from triSurface and bounding box.
		//  Holds references.
		octreeDataTriSurface(const triSurface&, const treeBoundBoxList&);


	// Member Functions

		// Access

			const triSurface& surface() const
			{
				return surface_;
			}

			const treeBoundBoxList& allBb() const
			{
				return allBb_;
			}

			label size() const
			{
				return allBb_.size();
			}


		// Search

			//- Get type of sample
			label getSampleType
			(
				const octree<octreeDataTriSurface>&,
				const point&
			) const;

			//- Does (bb of) shape at index overlap bb
			bool overlaps
			(
				const label index,
				const treeBoundBox& sampleBb
			) const;

			//- Does shape at index contain sample
			bool contains
			(
				const label index,
				const point& sample
			) const;

			//- Segment (from start to end) intersection with shape
			//  at index. If intersects returns true and sets intersectionPoint
			bool intersects
			(
				const label index,
				const point& start,
				const point& end,
				point& intersectionPoint
			) const;

			//- Sets newTightest to bounding box (and returns true) if
			//  nearer to sample than tightest bounding box. Otherwise
			//  returns false.
			bool findTightest
			(
				const label index,
				const point& sample,
				treeBoundBox& tightest
			) const;

			//- Given index get unit normal and calculate (numerical) sign
			//  of sample.
			//  Used to determine accuracy of calcNearest or inside/outside.
			scalar calcSign
			(
				const label index,
				const point& sample,
				vector& n
			) const;

			//- Calculates nearest (to sample) point in shape.
			//  Returns point and mag(nearest - sample)
			scalar calcNearest
			(
				const label index,
				const point& sample,
				point& nearest
			) const;

			//- Calculates nearest (to line segment) point in shape.
			//  Returns distance and both point.
			scalar calcNearest
			(
				const label index,
				const linePointRef& ln,
				point& linePt,          // nearest point on line
				point& shapePt          // nearest point on shape
			) const;


		// Write

			// Write shape at index
			void write(Ostream& os, const label index) const;


	// IOstream Operators

		friend Istream& operator>>(Istream&, octreeDataTriSurface&);
		friend Ostream& operator<<(Ostream&, const octreeDataTriSurface&);
};


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace Foam

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //


#include "octreeDataTriSurfaceTreeLeaf.H"

#endif

// ************************************************************************* //
